Manufacture of artificial threads or filaments



Patented v Apr. 2, 1935 i Beginald;Wi lliamf1ayne and, Robert Pierce [Rebel-ts, Spondon, .near Derby, England, as-

signorsitov Gelanese Corporation of America, a

' v corporationof Delaware I i v No Drawing. Application December 112, 1928,

.S'erialNo; 325,479,. In Great BritainDecember 4 ,2 Claims. (01. is-s'n 1- m i I invention relates to the manufacture of artificial filaments "or threads from solutions of cellulose acetate or other esters or ethers of cellulose by the dry spinning or evaporative method 5 of formation.

In the spinning of' such"'artificial threads or filaments by the dry or evaporative method of formation, solutions of organic cellulose derivatives (that is cellulose acetate or other esters or ethers of cellulose) in volatile solvents are spun into an evaporative atmosphere (usually into a current of heated air) the threads or filaments so formed being continuously wound up, with e or without twisting, on apparatus situated within or outside the evaporative atmosphere. The threads or filaments heretofore produced by such method of spinning have been lustrous in character and have found successful application as artificial silk, artificial horse hair and the like,

The object of the present invention is to pro duce threads or filaments presenting reduced lustre and more particularly threads or filaments presenting a dull matt or lustreless appearance, or of considerably reduced lustre.

For this purpose, according to the invention, we employ solutions of cellulose acetate or other organic esters or ethers of cellulose in volatile solvents and containing water, and we perform as spinning of said solutions by the dry or evaporative method under such; conditions that the water exerts a precipitating action on'the filaments in the natal state, of the filaments.

In performing the invention we may extrude into a heated casing or spinning cell (such for instance as described in U. S. Patents Nos..l,'602,125 and 1,541,104 and 1,731,317), through which a current of air is caused to pass, a solution containing cellulose acetateor other esters or ethers of cellulose and water. The quantity of water present in the spinning solution will vary according to the spinning conditions and the result it is desired to achieve.

In general, quantities of water from about or less to or more, and preferably 20% to r 39%, relatively to the volatile solvent should be employed, but it will be understood that these quantities are only given by way of illustration. The quantity of water employed in the spinning solution should of course be suflicient to cause a precipitation of the cellulose derivatives from solution under the spinning conditions employed. The following example serves to illustrate one form of the invention.

Example Highly satisfactory filaments, threads or yarns spinning cell through which a "curre caused topassin an upward or downwarddirection. Y I

, $l 0 i; I [Parts by weight] 1 J a b c v Q Acetone sa -100% pure... 72 7s 7s 84 92 Water 28 24- 22 16 8 Cellulose acetate 33% 33% 33% 33% 33% Thedegree of delustration produced willvary I with the temperature of the heated air. Thus with a current of air heated'to a temperature of C. each of the above solutions will yield delustred artificial filaments, the filaments produced from'solutions a or b being substantially completely delustred andpresenting a dull matt appearance, the filaments produced from solutf bf air tions 0 or (2 being very dull'but slightly more lustrous than those produced from solution a or 2), whereas filaments .produced from solution e are only slightly delustred. With increasing temperatures of the heated air the degree of delustration imparted to the filaments will decrease, for instance, with a current ofair heated to a temperature of 65 C. solutions a or I) yield slightly delustred filaments, whereas solutions 0 or a! yield bright filaments of but slightly reduced lustre. Solution e should not be spun with an air current exceeding temperatures of about 50 to60 0., otherwise the water will not actias a precipitant and highly lustrous filaments will I In performing the invention we preferably wind 1 result.

the filaments up (continuously withtheir formation) with or without twisting, on apparatus located outside the evaporative atmosphere, though 0 such winding may be performed within said atmosphere if so desired.

It is to be understood that the invention "is in no way limited to the particular example of exej cution described which may be varied widely.

The filaments may be extruded either down wards or upwards into the spinning 'cellor metier casing, and the-air current (which may be caused to pass either upwards or downwards through the metiercasing or cell) may be heated or warmed therein or prior to admission thereto or both before and during passage through the cell or metier casing. Further, the filaments may be extruded in the same direction as 'orcounter-current to the air current.

The temperature to be employed in the spin-j ning cells or metier casings may vary with the boiling point of the solvents used, the composition of the spinning solutions and the degree of delus- .tration it is desired to produce in the filaments or threads. Such temperatures may be higher or so f lower than theboiling-point or points 01- the solvent or solvents employed. p 1 t ,We have found that with spinning solutions c ontaining the more usual solvents such as acetone;

methyl acetate or the like,-temperatures of-about to, 80 C. may usefully beemployediin the spinning cells or metier casings, but we in no way limit ourselves to such temperatures.

, By means of the presentinvention it is possible'; to obtain threads or filaments showing any deent in thespimiing solution the greater will be 'fthe degree 1 of delustration obtained under similar spinning conditions, and the greater the temperature employed for spinning a solution of given water content the less will be the degree of delustration obtained.

-ments presenting reduced luster comprising form- .ing fllament'sfrom solutions of cellulose acetate What we claim and desire to secureby' Letters Patentis: j. 1. Process for the production or artificial filain a volatile solvent comprising acetone and between 10% and 30% of water, relatively to, the

" volatile solvent, by'thedry or evaporative methsod under. such conditions that the water exertsa, precipitating action on the filaments in the natal stateoi'the filaments. 2; ,Method' of producing artificialfilamentspresenting reduced luster which comprises extruding into'a current of air heated to a temperature'between and C. a solution of cellulose acetate 10 composedof between72 and 84 parts of acetone,

between 28 and 16 parts-o1 water parts i of: cellulose acetate REGINALD WILLIAM PAYNE ,BOBERT PIERCE ROBERTS. 

